Fruit and Appetite

I've been reading about leptin recently. It is a protein hormone which regulates metabolism and appetite.

I have for a while suspected that certain foods decrease appetite satisfaction more or less than other foods. Specifically, that "junk food" is less likely to satisfy appetite. The effect certain nutrients have on leptin seems to verify this.

Studies (here's one) have shown that fructose specifically (uniquely among all types of sugar) increases "leptin resistance" which basically mean your body isn't as receptive to leptin and your appetite doesn't go down as you eat like it should. Eating fructose suppresses appetite reduction that would otherwise normally occur.

Eating a lot of meat or fat should make you feel full since it's calorie-dense food. But if you have a glass of Coke with your food, you're not going to feel as full after or while you eat. You're going to eat more.

I've read a few evolutionarily-minded people suggest that prehistoric humans ate fruit (and thus, fructose) only seasonally, at times when they needed to put on weight to prepare for winter, and I agree this makes sense. Fruit-bearing plants also benefit evolutionarily by this effect, since they need fruit-eaters to digest and distribute their seeds.

So, despite that the corn lobby's commercials are correct in saying high fructose corn syrup is identical to regular sugar (sucrose) in many ways (calories per gram, etc), fructose is NOT biochemically identical to sucrose.

My advice would be to stay away from high fructose corn syrup containing foods, and to keep fruit in moderation ONLY, especially if your diet consists of high calorie foods that are easy to overconsume. You should find yourself, over time, being more satisfied by less food as a result.